11 Vintage Silver Plate Knives

These 11 silver knives have no markings. I aquired them at an estate sale. I *think* they are silver plated from International Silver Co XII. They all have surface scratches, but overall are in good condition for their age. They have been hidden away for decades wrapped in heavy duty foil to try to prevent tarnishing. Picture # 2 shows that 4 of the knives have a bit of reddish colored markings on the base of the knive. I don't know what it is and I have NOT tried to clean them. Picture # 3 shows how they have been stored in foil.